Astronomy & Astrophysics Seminar: The CARMENES search for extra-solar planets around M-dwarf stars
Dr. Lev Tal-Or, Institut fur Astrophysik (IAG), Goettingen, Germany
Despite thousands of planetary systems discovered around Solar-like stars in the past 30 years, the fraction of planets detected around lower-mass stars (namely M dwarfs) is still way below their representation in the Galaxy. M stars bring both great promise and great challenge for planet detection---their lower mass and luminosity makes the Doppler signatures of their low-mass habitable-zone planets detectable by nowadays radial-velocity (RV) instruments, but their faintness and low surface temperatures make such measurements challenging for visible-light instruments.
The CARMENES instrument and survey was designed to address these challenges. Using a high-resolution dual-channel (red-optical and infrared) spectrograph, CARMENES is designed to provide M-star RV measurements with a precision of <3 m/s. The CARMENES survey started on Jan 1, 2016, with its main goal of probing ∼ 300 nearby, single, M-dwarf stars to investigate the architectures of their inner planetary systems. In this talk I will give a brief overview of the current status of the instrument performance and science results. I will also discuss yet another challenge in precise RV measurements of M dwarfs---the ways their stellar magnetic activity and rotation impact their spectra and RVs.
Seminar Organizer: Prof. Sara Beck